Charge equalization apparatus

Abstract

The present invention relates to a charge equalization apparatus, which allows the primary and secondary windings of a transformer to be easily fabricated, can control the flow of charge to batteries depending on the charged states of series-connected batteries, and can prevent overcurrent from flowing into a battery currently being charged.

1. A charge equalization apparatus, comprising:
 N transformers connected in parallel to N respective series-connected batteries, and configured to each include one primary winding and two secondary windings and to charge batteries, other than the overcharged batteries, with energy discharged from the overcharged batteries; 
 a first charge storage device and a second charge storage device each connected in parallel to the N series-connected battery and the N transformer; 
 a first redistribution switch and a second redistribution switch connected in series between the first and second charge storage devices and the N transformers; 
 charge control switches each connected to both ends of a primary winding of each of the N transformers; 
 N first semiconductor switching elements each connected to a first secondary winding of each of the N transformers and a positive electrode of each of the N batteries; and 
 N second semiconductor switching elements each connected to a second secondary winding of each of the N transformers and a positive electrode of each of the N batteries. 
 
     
     
       2. The charge equalization apparatus as set forth in  claim 1 , wherein the first semiconductor switching elements and the second semiconductor switching elements are each any one of a MOSFET, a BJT, a relay and a diode. 
     
     
       3. The charge equalization apparatus as set forth in  claim 2 , wherein the first semiconductor switching elements and the second semiconductor switching elements are diodes. 
     
     
       4. The charge equalization apparatus as set forth in  claim 3 , wherein the charge control switches, the first redistribution switch and the second redistribution switch are each any one of a MOSFET, a BJT, and a relay. 
     
     
       5. The charge equalization apparatus as set forth in  claim 4 , wherein the charge control switches, the first redistribution switch and the second redistribution switch are and the redistribution switch are N-type MOSFETs. 
     
     
       6. The charge equalization apparatus as set forth in  claim 5 , wherein a turns ratio of a primary winding of each of the N transformers to a secondary winding thereof is N 1 :N 2 , which is identical for the first secondary windings and the second secondary windings. 
     
     
       7. The charge equalization apparatus as set forth in  claim 6 , wherein polarities of the primary windings, the first secondary windings and the second secondary windings are identical to each other. 
     
     
       8. The charge equalization apparatus as set forth in  claim 7 , wherein a common node of each of the first secondary windings and each of the second secondary windings is connected to a negative electrode of each of the batteries. 
     
     
       9. The charge equalization apparatus as set forth in  claim 8 , wherein the voltage detection and drive signal generation unit comprises:
 a sensing unit for detecting voltages of the N batteries; 
 a microprocessor for setting ON/OFF time of the charge control switches and the redistribution switch based on the voltages detected by the sensing unit; and 
 a switch driving circuit unit for generating a first drive signal and a second drive signal for driving the charge control switches and the redistribution switch in response to signals input from the microprocessor. 
 
     
     
       10. The charge equalization apparatus as set forth in  claim 9 , wherein the first charge storage device and the second charge storage device are each any one of a capacitor and a battery. 
     
     
       11. The charge equalization apparatus as set forth in  claim 10 , wherein the first charge storage device and the second charge storage device are capacitors.